/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.fontbox.ttf;

import java.io.IOException;

/**
 * This class is based on code from Apache Batik a subproject of Apache XMLGraphics.
 * see http://xmlgraphics.apache.org/batik/ for further details.
 * 
 */
public abstract class GlyfDescript implements GlyphDescription 
{

    // Flags describing a coordinate of a glyph.
    /**
     * if set, the point is on the curve.
     */
    public static final byte ON_CURVE = 0x01;
    /**
     * if set, the x-coordinate is 1 byte long.
     */
    public static final byte X_SHORT_VECTOR = 0x02;
    /**
     * if set, the y-coordinate is 1 byte long.
     */
    public static final byte Y_SHORT_VECTOR = 0x04;
    /**
     * if set, the next byte specifies the number of additional 
     * times this set of flags is to be repeated.
     */
    public static final byte REPEAT = 0x08;
    /**
     * This flag as two meanings, depending on how the
     * x-short vector flags is set.
     * If the x-short vector is set, this bit describes the sign
     * of the value, with 1 equaling positive and 0 positive.
     * If the x-short vector is not set and this bit is also not
     * set, the current x-coordinate is a signed 16-bit delta vector.
     */
    public static final byte X_DUAL = 0x10;
    /**
     * This flag as two meanings, depending on how the
     * y-short vector flags is set.
     * If the y-short vector is set, this bit describes the sign
     * of the value, with 1 equaling positive and 0 positive.
     * If the y-short vector is not set and this bit is also not
     * set, the current y-coordinate is a signed 16-bit delta vector.
     */
    public static final byte Y_DUAL = 0x20;

    private int[] instructions;
    private final int contourCount;

    /**
     * Constructor.
     * 
     * @param numberOfContours the number of contours
     */
    GlyfDescript(short numberOfContours) 
    {
        contourCount = numberOfContours;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void resolve() 
    {
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int getContourCount() 
    {
        return contourCount;
    }

    /**
     * Returns the hinting instructions.
     * @return an array containing the hinting instructions.
     */
    public int[] getInstructions() 
    {
        return instructions;
    }

    /**
     * Read the hinting instructions.
     * @param bais the stream to be read
     * @param count the number of instructions to be read 
     * @throws IOException is thrown if something went wrong
     */
    void readInstructions(TTFDataStream bais, int count) throws IOException
    {
        instructions = bais.readUnsignedByteArray(count);
    }

}
